Method for the use of nitrates and nitrate reducing bacteria in hydraulic fracturing

Abstract

A slick water fracturing fluid including a brine, an inorganic nitrate, a nitrogen reducing bacteria, a scale inhibitor selected from the group consisting of a polyacrylate polymer, a polyacrylate copolymer, a polyacrylate terpolymer, and mixtures thereof, and a friction reducer, wherein the friction reducer is a polyacrylamide.

What is claimed is: 
     
       1. A method of controlling sulfides in a subterranean formation, comprising:
 injecting a fluid comprising an inorganic nitrate and a friction reducer into the subterranean formation; and 
 allowing the inorganic nitrate to increase the growth rate of nitrogen-reducing bacteria in the formation so as to inhibit the growth rate of sulfate-reducing bacteria in the formation. 
 
     
     
       2. The method of  claim 1  wherein the inorganic nitrate is selected from the group consisting of potassium nitrate, sodium nitrate, ammonium nitrate, and mixtures thereof. 
     
     
       3. The method of  claim 1  further comprising: injecting nitrogen reducing bacteria into the subterranean formation. 
     
     
       4. The method of  claim 1  wherein the nitrogen reducing bacteria is selected from the group consisting of  Campylobacter  sp.  Nitrobacter  sp.,  Nitrosomonas  sp.,  Thiomicrospira  sp.,  Sulfurospirillum  sp.,  Thauera  sp.,  Paracoccus  sp.,  Pseudomonas  sp.,  Rhodobacter  sp.,  Desulfovibrio  sp., and mixtures thereof. 
     
     
       5. The method of  claim 4  wherein nitrogen reducing bacteria is  Nitrobacter vulgaris, Nitrosomonas europea, Pseudomonas stutzeri, Pseudomonas aeruginosa, Paracoccus denitrificans, Sulfurospirillum deleyianum , and  Rhodobacter sphaeroides.    
     
     
       6. The method of  claim 1  further comprising: injecting a molybdate or molybdate salt into the subterranean formation. 
     
     
       7. The method of  claim 6  wherein the molybdate salt is selected from the group consisting of sodium molybdate, lithium molybdate, and mixtures thereof. 
     
     
       8. The method of  claim 1  further comprising: injecting 9, 10-anthraquinone into the subterranean formation. 
     
     
       9. The method of  claim 1  wherein no effective amount of a biocide is introduced into the subterranean formation. 
     
     
       10. The method of  claim 1  wherein the subterranean formation comprises a low permeability subterranean formation. 
     
     
       11. The method of  claim 1  wherein the fluid further comprises a brine. 
     
     
       12. The method of  claim 1  wherein the fluid further comprises a scale inhibitor. 
     
     
       13. The method of  claim 1  wherein the fluid further comprises a molybdate or molybdate salt. 
     
     
       14. The method of  claim 1  wherein the fluid further comprises 9, 10-anthraquinone. 
     
     
       15. A method of controlling sulfides in a subterranean formation, comprising:
 injecting a fluid comprising an inorganic nitrate into the subterranean formation, wherein the fluid comprises a gel; and 
 allowing the inorganic nitrate to increase the growth rate of nitrogen-reducing bacteria in the formation so as to inhibit the growth rate of sulfate-reducing bacteria in the formation. 
 
     
     
       16. The method of  claim 15  wherein the fluid does not comprise an effective amount of a biocide. 
     
     
       17. The method of  claim 15  wherein the fluid further comprises a molybdate or molybdate salt. 
     
     
       18. The method of  claim 15  wherein the fluid further comprises 9, 10-anthraquinone. 
     
     
       19. The method of  claim 15  wherein the fluid further comprises a scale inhibitor. 
     
     
       20. The method of  claim 15  wherein the fluid further comprises a brine.